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Search results for: UNKNOWN MECHANICAL MODEL
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Effect of Glass Powder on the Cement Hydration, Microstructure and Mechanical Properties of Mortar
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The effects of silica/titania nanocomposite on the mechanical and bactericidal properties of cement mortars
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The Influence of Silica Fume on the Mechanical and Thermal Parameters of Portland Cement Concretes
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Mechanical characterization of a gravel column in a calibration chamber operating as a triaxial cell
PublicationA series of tests considering the behavior of gravel columns was performed. A segment of column with a height of 1 m and a diameter of 0.53 m was modelled in a calibration chamber used as a triaxial cell at three different lateral stress applied. The vertical load transferred on the column head was simulated with steady increase of water pressures in the upper and lower membranes. During the loading the volumetric changes in the...
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Assessment of fatigue damage of organic coatings subjected to cyclic mechanical stress
PublicationTechnika szumu elektrochemicznego od ponad 20 lat stanowi przedmiot intensywnych badań mających na celu jej praktyczne zastosowanie w monitorowaniu korozji. U podstaw omawianej metody leży odpowiednia analiza rejestrowanych symultanicznie przebiegów prądowych i potencjałowych. W zależności od użytej techniki obróbki danych uzyskane mogą być informacje dotyczące ilościowych (szybkość) i jakościowych (rodzaj zaatakowania) cech procesu...
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Geometric methods in dynamical systems modelling: electrical, mechanical and control systems
PublicationRozważono zagadnienia modelowania systemów dynamicznych z zastosowaniem metod geometrii różniczkowej. Równania dynamiczne otrzymano w postaci inkluzji różniczkowych. Przestrzenie konstytucyjne przyjęto w postaci subwiązek włóknistych. Rozważono przestrzenie konstytucyjne układów elektrycznych, układów mechanicznych i układów sterowania. Podstawowe wyniki pracy dotyczą struktury przestrzeni rozwiązań rozważanych systemów.
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Influence of deformation velocity on mechanical properties of high strength structural steels.
PublicationW referacie przedstawiono wyniki badań własności mechanicznych stali wysokiej wytrzymałości przeznaczonych na spawane konstrukcje okrętowe w zależności od prędkości odkształcenia. Badania były prowadzone w Akademii Marynarki Wojennej oraz w Politechnice Gdańskiej przy współudziale Uniwersytetu Technicznego w Rostocku podczas opracowywania charakterystyk tych stali dla potrzeb polskiego przemysłu okrętowego. Uwzględnienie obciążeń...
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Modelling of mechanical properties of cooper alloys sand cast ship propellers.
PublicationBadania właściwości mechanicznych (Rm ,A5) stopów miedzi, stosowanych na pędniki okrętowe, w zależności od ich składu chemicznego i grubości odlewów piaskowych pozwalają na wyznaczenie równań regresji mających zastosowanie do prognozowania wytrzymałości statycznej na rozciąganie (Rm) i wydłużenia plastycznego (A5).Obliczenia wartości Rm i A5 dla wybranych odlewów piaskowych (mosiądz MM55, brązy BA93, BA2 i CMA1) wykazały, że opracowane...
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Flow boiling intensification in minichannels by means of mechanical flow turbulising inserts
PublicationThe work presents the results of experimental investigation on heat transfer in minichannels. Refrigerant R123 was used as a test fluid. Single vertical silver tubes of 380 mm length and 2.3 mm diameter were examined with two variants of turbulising inserts. A wide range of parameters was considered, namely mass flux G=534-3011 kg/(m2s), heat flux qw=28.5-68.4 kW/m2, saturation temperature Tsat=23-86 stC and the full range of vapour...
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Mechanical Properties of Single-Walled Carbon Nanotubes with AIREBO Force-Filed
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Structural and physico-mechanical properties of natural rubber/GTR composites devulcanized by microwaves: Influence of GTR source and irradiation time
PublicationGround tire rubber from car and truck was modified using microwave irradiation at variable time. The irradiated ground tire rubber was used as filler in composites based on natural rubber. The composites, with high content of ground tire rubber, were prepared using an internal batch mixer and subsequently cross-linked at 160℃. The influence of the ground tire rubber source (car/truck) and irradiation time on structure, physico-mechanical...
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Developing a model of cooperation between universities and business - the generalization of cases of cooperation
PublicationThe aim of this paper is to present a model of cooperation between universities and business.
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A simplified behavioral MOSFET model based on parameters extraction for circuit simulations.
PublicationThe paper presents results on behavior modeling of general purpose Metal-Oxide Semiconductor Field-Effect Transistor (MOSFET) for simulation of power electronics systems requiring accuracy both in steady-state and in switching conditions. Methods of parameters extraction including nonlinearity of parasitic capacitances and steady-state characteristics are based on manufacturer data sheet and externally measurable characteristics....
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Scheduling jobs to contain a natural disaster: a model and complexity
Publicationthis paper is devoted to the problem of scheduling suppression units so that a natural disaster is dealt with as efficient as possible. the concept of deteriorating jobs is adopted, that is, the formal model of scheduling represents linearly increasing value loss as the disaster remains unsuppressed and increasing time for its suppression. more precisely, two different goals are considered: finding a suppression schedule of minimal...
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Some results on trading model in a consensus list coloring
PublicationKonsensusowy model kolorowania grafów - uogólnienie kolorowania listowego, został zdefiniowany przez Mahadeva i Robertsa w 2002 jako użyteczne narzędzie teoretyczne w niektórych zagadnieniach bioinformatycznych. Pozostaje on jednak słabo rozpoznany pod względem własności algorytmicznych. Wykazujemy, że problem kolorowania grafów pełnych w tym modelu jest wielomianowy, co można uogólnić na częściowe k-drzewa przy ustalonym ograniczeniu...
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Model of heat transfer in the stagnation point of rapidly evaporating microjet
PublicationThe paper presents investigation in the single water microjet surface cooling producing evaporating film. Reported tests were conducted under steady state conditions. It was proved that the phenomenon is similar to that of pool boiling. Results of experiments were compared with predictions by the model showing a good consistency.
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Model przepływu wód podziemnych w gdańskim systemie wodonośnym
PublicationGdański system wodonośny jest systemem wielowarstwowym. Obejmuje on kilka poziomów zawartych w trzech piętrach wodonośnych: czwartorzędowym, trzeciorzędowym i kredowym. Dla tak określonego systemu wykonano model przepływu wód podziemnych i określono poszczególne składniki bilansu przepływu.
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Mutually polarizable QM/MM model with in situ optimized localized basis functions
PublicationWe extend our recently developed quantum-mechanical/molecular mechanics (QM/MM) approach [Dziedzic et al., J. Chem. Phys. 145, 124106 (2016)] to enable in situ optimization of the localized orbitals. The quantum subsystem is described with ONETEP linear-scaling density functional theory and the classical subsystem – with the AMOEBA polarizable force field. The two subsystems interact via multipolar electrostatics and are fully...
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A Numerical Model Study on Grasse River Ice Control Structures
PublicationIce jams in the Grasse River have caused the erosion of capping material designed to prevent the resurfacing of the bed sediment in the PCB-contaminated area. Two in-stream ice-control structures are proposed to avoid the jam-induced erosion of the capping material. These two ice-control options are a pier-type ice-control structure and a reconstruction of a small hydropower dam upstream of the capping site. A numerical model study...
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Impedance spectra of ZnO varistor type 440 model A ver. M
Open Research DataThe impedance spectrum of high-voltage ZnO varistor obtained using FRA EIS impedance spectrosocpy measurement method. The 1V sinusoidal excitation was used. The frequency range was chosen from 10 kHz down to 100 uHz. The object under test and the measuring instrument were placed in a Faraday cage due to high impedance of the object. The data was acquired...
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Impedance spectra of ZnO varistor type 280 model A ver. M
Open Research DataThe impedance spectrum of high-voltage ZnO varistor obtained using FRA EIS impedance spectrosocpy measurement method. The 1V sinusoidal excitation was used. The frequency range was chosen from 10 kHz down to 100 uHz. The object under test and the measuring instrument were placed in a Faraday cage due to high impedance of the object. The data was acquired...
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Four-state stochastic model of changes in the reliability states of a motor vehicle
PublicationThe properties of semi-Markov processes have been generally characterized and the applicability of the theory of such processes to the determining of the reliability of motor cars and other road vehicles has been explained. A formal description of the process of changes in the motor vehicle technical states considered as reliability states and a model of this process in the form of a one-dimensional stochastic process have been...
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Geometry Parametric Model Order Reduction with Randomly Generated Projection Bases
PublicationIn this work, a reduced-order model for geometry parameters and fast frequency sweep is proposed. The Finite Element Method is used to solve time-harmonic Maxwell’s equations. Taking into account the electromagnetic field does not arbitrarily vary as a function of frequency and geometry parameters, a low dimension system manifold is identified. Thus, the original Finite Element problem can be approximated by a model of reduced...
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Developing a methodology for model tests of floating platforms in a towing tank of low depth
PublicationThe paper presents two ways to mooring model of semi-submersible platform for research in the small depth towing pool. The tested model was made in the likeness of 1:100 Thunder Horse platform moored in the Gulf of Mexico at a depth of 1,920 m. Its mooring system consisted of 16 semi-taut mooring lines (chain-wire-chain) spaced Star-shape and attached at the bottom to the suction piles. The tests were performed in the towing pool...
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A model development and experimental verification for a vapour microturbine with a permanent magnet synchronous generator
PublicationVapour microturbines with permanent magnet synchronous generators are implemented in micropower plants for dispersed power generation systems. The dynamic model of such a microturbine set was developed and presented. The developed relations result from the generic equations. Experimental data for two different working medium were used for model verification. A microturbine set model was tested during the changes in the parameters...
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Modelling of fracture process in brittle materials using a lattice model
PublicationW artykule przedstawiono wyniki obliczeń propagacji rys w elementach betonowych przy zastosowaniu modelu dyskretnego opartego na ruszcie belkowym. Obliczenia wykonano dla różnych problemów brzegowych. Dla redukcji kruchości w obszarze pokrytycznym przyjęto model nielokalny obliczenia odkształceń.
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Stałoprądowy model tranzystora mos dla zakresu przed- i nadprogowego
PublicationZaprezentowano spójny fizycznie, stałoprądowy, jednosekcyjny model opisujący pracę tranzystora MOS zarówno w zakresie przed- i nadprogowym, jak również w zakresie liniowym (triodowym) i nasycenia (pentodowym). Przedstawiono założenia modelu fizycznego w przestrzeni 2-D i jego transformację do modelu quasi-dwuwymiarowego praz zademonstrowano wyniki weryfikacji eksperymentalnej modelu. Model spełnia warunek symetrii Gummel'a
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Topological-numerical analysis of a two-dimensional discrete neuron model
PublicationWe conduct computer-assisted analysis of a two-dimensional model of a neuron introduced by Chialvo in 1995 [Chaos, Solitons Fractals 5, 461–479]. We apply the method of rigorous analysis of global dynamics based on a set-oriented topological approach, introduced by Arai et al. in 2009 [SIAM J. Appl. Dyn. Syst. 8, 757–789] and improved and expanded afterward. Additionally, we introduce a new algorithm to analyze the return times...
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Quantum corrections to phi^4 model solutions and applications to Heisenberg chain dynamics
PublicationThe Heisenberg spin chain is considered in φ^4 model approximation. Quantum corrections to classical solutions of the one-dimensional φ^4 model within the correspondent physics are evaluated with account of rest d−1 dimensions of a d-dimensional theory. A quantization of the model is considered in terms of spacetime functional integral. The generalized zeta-function formalism is used to renormalize and evaluate the functional integral...
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Fish gelatin-nanoclay films. Part I: Effect of a kind of nanoclays and glycerol concentration on mechanical and water barrier properties of nanocomposites
PublicationThe aim of work was the improvement of the mechanical and water barrier properties of nanocomposites prepared from fish gelatin and nanoclays (5–15%), plasticized with glycerol at different concentrations. The effect of hydrophilic Cloisite Na1 and Nanomer®PGV was compared with that exerted by organically modified more hydrophobic Nanofil®2 and NanoBent ZR-1. Antimicrobial activity of nanocomposites containing hydrophobic nanoclays...
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Enhanced interfacial and mechanical performance of styrene-butadiene rubber/silica composites compatibilized by soybean oil derived silanized plasticization
PublicationSilanized plasticizer (SP) was chemically derived and synthesized from soybean oil (SBO) co-vulcanized with bis-(3-(triethoxysilyl)-propyl) tetrasulfide (TESPT) by using the sulfur-accelerated curing system. SP extended styrene-butadiene rubber (SBR)/silica composites have been studied for their improved filler dispersion through coupling interaction at the SBR/silica interface. The effect of SP on cross-link density, thermal,...
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Wirtualny model zbiorników z wodą w sterowniku PLC
PublicationModele obiektów rzeczywistych otrzymuje się na różnorodne sposoby i wykorzystuje w różnorodnych celach. Do badania obiektów automatyki stosuje się najczęściej programy komputerowe, np.: Matlab-Simulink, Scilab, GNU Octave, itp. Można również stosować pamięć operacyjną sterowników [1, 2]. W referacie przedstawiono opis wirtualnego modelu dwóch połączonych zbiorników z wodą w sterowniku PLC. Proste przekształcenia matematyczne pozwalają...
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Positive Management of Universities: A Model of Motivation to Strive for Scientific Excellence
PublicationObjective: The aim of the article is to conceptualise a model of work motivation in the management of universities striving for scientific excellence. Research Design & Methods: The most relevant for our aim is the self-determina tion theory that is applied to the work and organisational domain. We used a nar rative literature review. Findings: The proposed model is derived from the self-determination theory. It includes three...
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MULTI-CRITERIA MODEL IN MULTIFUNCTIONAL BUILDING SYSTEM DESIGN PROCESS
PublicationThe paper presents a multi-criteria approach in multifunctional building system design process. The aim is to develop a theory relative to the engineering system of multifunctional with a mathematical representation defined by a holistic network for the lifecycle of the designed object. The idea of work was to define the structure of a complex system. Background for the presented field is to develop a design strategy for multifunctional...
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Static and dynamic concrete calculations: Breakable aggregates in DEM model
PublicationThe paper deals with the calculations of a 3-point bending beam under static and dynamic loads. The real microstructure was obtained from laboratory tests using micro-tomography images. The quasi-static results were compared directly with experimental data at both macro and micro levels. Subsequently, higher strain rates were applied to investigate dynamic effects. The study focused on the influence of dynamic loading on the macroscopic...
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Model ontologiczny referencyjnego problemu planowania misji inspekcyjnych
PublicationRozważany problem doboru, alokacji i planowania działań grupy robotów inspekcyjnych w środowisku pomieszczeń zamkniętych sformułowany został w modelu deklaratywnym. Zaproponowany model definiowany przez zbiór zmiennych decyzyjnych charakteryzujących środowisko pomieszczeń zamkniętych z nieruchomymi i poruszającymi się przeszkodami a także flotę robotów mobilnych oraz zbioru ograniczeń wiążących te zmienne, wyrażany jest w postaci...
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Model pomiaru spirometrycznego - zastosowanie w diagnostyce pulmonologicznej
PublicationBadanie spirometryczne określa jakość wentylacji płuc. Funkcjonowanie układu oddechowego oparte jest na mechanizmie wentylacji. Podstawowymi zaburzeniami układu oddechowego są zmiany o charakterze obturacyjnym, restrykcyjnym oraz mieszanym. W pracy zaprezentowano nowy model badania spirometrycznego. Estymaty parametrów modelu wyliczane są na podstawie wyników spirometrii. Parametry modelu dostarczają nowych informacji na temat...
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The concept of knowledge bases supporting the it systems integration model
PublicationThis paper presents main concepts regarding the design of a knowledge base in order to support IT systems integration. The main goal of the research is to develop a universal method of integration of various systems concerning any possible area of interest. The concept is based on creating a generic mechanism which would support the decision regarding the choice of the integration model. The most important tasks include: key factors...
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Fast Low-fidelity Wing Aerodynamics Model for Surrogate-Based Shape Optimization
PublicationVariable-fidelity optimization (VFO) can be efficient in terms of the computational cost when compared with traditional approaches, such as gradient-based methods with adjoint sensitivity information. In variable-fidelity methods, the directoptimization of the expensive high-fidelity model is replaced by iterative re-optimization of a physics-based surrogate model, which is constructed from a corrected low-fidelity model. The success...
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Dynamiczny model uogólnionego łącznika energoelektronicznego do symulacji układów przekształtnikowych
PublicationZaproponowano strategię modelowania, w której po określeniu postaci modelu dobiera się numeryczne metody obliczeniowe stosowane w symulacji. Przedstawiono opracowany uogólniony, nieliniowy model tranzystora mocy IGBT. Przyjęto, że do określenia parametrów tego modelu powinna wystarczać znajomość standardowych, katalogowych para-metrów i charakterystyk. Przedstawiono model zaciskowy o klasycznej strukturze, odwzorowujący z wystarczającą...
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Mechanical properties of VL E27 steel for shipbuilding – Charpy impact test reslut in vary tempetatures
Open Research DataOne of the basic divisions of steels used for ship hulls and ocean engineering structures is the division into: normal strength steels, high strength steels and extra high strength steels. The belonging to the group is determined by the mechanical properties of the steel, such as: yield point, ultimate strength and plastic elongation after fracture....
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Mechanical properties of VL E27 steel for shipbuilding – tensile test in +20°C, elastic modulus
Open Research DataOne of the basic divisions of steels used for ship hulls and ocean engineering structures is the division into: normal strength steels, high strength steels and extra high strength steels. The belonging to the group is determined by the mechanical properties of the steel, such as: yield point, ultimate strength and plastic elongation after fracture....
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Autonomous Ship Utility Model Parameter Estimation Utilising Extended Kalman Filter
PublicationIn this paper, a problem of autonomous ship utility model identification for control purposes is considered. In particular, the problem is formulated in terms of model parameter estimation (one-step-ahead prediction). This is a complex task due to lack of measurements of the parameter values, their time-variability and structural uncertainty introduced by the available models. In this work, authors consider and compare two utility...
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Survival time prognosis under a Markov model of cancer development
PublicationIn this study we look at a breast cancer data set of women from Pomerania region collected in year 1987-1992 in the Medical University of Gdańsk. We analyze the clinical risk factors in conjunction with Markov model of cancer development. We evaluate Artificial Neural Network (ANN) survival time prediction via a simulation study.
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The QDMC Model Predictive Controller for the Nuclear Power Plant Steam Turbine Control
PublicationThere are typically two main control loops with PI con trollers operating at each turbo-generator set. In this paper a model predictive controller QDMC for the steam turbine is proposed - instead of a typical PI controller. The QDMC controller utilize a step-response model for the controlled system. This model parameters are determined, based on the simplified and linear model of turbo-generator set, which parameters are identified...
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Model hydrodynamiczny cyrkulacji w instalacjach c.w.u.
PublicationW referacie opisano formalnie poprawny, kompletny model matematyczny cyrkulacji ciepłej wody użytkowej. Przedstawiono oznaczony układ równań dla przykładowej, niewielkiej lecz dostatecznie dużej i kompletnie wyposażonej instalacji. Policzono i zbilansowano liczbę równań i niewiadomych. Wskazano preferowane metody rozwiązywania takiego układu równań. Jest to materiał oryginalny (opracowany przez autorów od początku do końca), do...
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Nonlinear rate dependent model of high damping rubber bearing.
PublicationCelem artykułu jest analiza nieliniowego modelu łożyska wykonanego z wysokotłumiącej gumy, który symuluje pracę urządzenia pod zadanym obciążeniem. Parametry modelu dobrane są na podstawie wyników badań eksperymentalnych. Wyniki pracy pokazują, iż analizowany model umożliwia symulację zachowania się łożyska w szerokim zakresie odkształceń
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Mathematical analysis of a generalised p53-Mdm2 protein gene expression model
PublicationWe propose the generalisation of the p53-Mdm2 protein gene expression model introduced by Monk (2003). We investigate the stability of a unique positive steady state and formulate conditions which guarantee the occurrence of the Hopf bifurcation. We show that oscillatory behaviour can be caused not only by time lag in protein transcription process, but also can be present in the model without time delay. Moreover, we investigate...
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Threshold Attendance under Soft-Crash Model: TAG Protocol and Markovian Analysis
PublicationA realistic and systematic network evaluation should subsume an availability model and a failure model. We combine a "hard availability" model we call threshold attendance, whereby a certain minimum number of network elements must be present at any time, with a soft-crash failure model, whereby after experiencing a failure, a network element is still able to function correctly for a while in an emergency mode at a risk of a major...
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Critical Case Stochastic Phylogenetic Tree Model via the Laplace Transform
PublicationBirth–and–death models are now a common mathematical tool to describe branching patterns observed in real–world phylogenetic trees. Liggett and Schinazi (2009) is one such example. The authors propose a simple birth–and–death model that is compatible with phylogenetic trees of both influenza and HIV, depending on the birth rate parameter. An interesting special case of this model is the critical case where the birth rate equals the...